Hi Steve,
Since you have created a test actor ref beforehand, `toProvider` would give the same instance every time it is injected. On the other hand the code you have shown looks a bit unusual to me. The binding `bind toProvider myActor` will have only one identifier of type `ActorRef`. For such a generic types I would always recommend to use additional identifiers (like string for example: `bind [ActorRef] identifiedBy "paymentProcessor" toProvider myActor`) in order to disambiguate it. Otherwise you can only define it only once in DI container.
I find it hard to give a suggestion based on the code you have shown. It would be very helpful if you could demonstrate how this actor or `ActorRef` is used in application (non-test) code. (I assume that you are overriding some existing application's `ActorRef` in the test with `TestActorRef`)
Cheers,
Oleg